A typical process of manufacturing a semiconductor device or an LCD, processing liquid includes supplying a processing liquid to a substrate, such as a semiconductor wafer or a glass substrate for an LCD panel, and a liquid processing of a surface of the substrate, or a thin film formed on the surface (“a liquid processing method”).
A liquid processing method for cleaning a wafer has been suggested to include, for example, discharging a mixed aqueous solution of ammonia and hydrogen peroxide (a first processing liquid) to a substrate, such as a wafer while rotating the wafer and discharging a hydrofluoric acid (a second processing liquid) to the wafer while rotating the wafer to clean the wafer. Examples of such method are disclosed in Japanese Patent Laid-open Publication Nos. 2002-329696 and 2008-60203.
Due to a cost and environmental reason, some processing liquids is reused. Thus, when processing liquid is performed with first and second processing liquids, a separate collection of the first and second processing liquids would be required without mixing the first and second processing liquids.
A liquid processing apparatus to perform the liquid processing method includes a cup provided at an outside the circumferential periphery of the wafer, to guide the processing liquid shaken off from the wafer toward the outside while the wafer rotates. However, the processing liquid splashing from the cup may be scattered as mist and may reach the surface of the wafer, thereby causing a defect such as watermarks or particles.